The present disclosure relates to an electromechanical brake tightening device, particularly for a rail vehicle brake.
Currently, three braking systems are essentially used in the rail vehicle sector: Electropneumatic braking systems, electrohydraulic braking systems as well as electromechanical braking systems. The braking system may be constructed as an active or passive braking system, depending on whether the force of a brake actuator has to be applied for braking (active braking system) or for releasing the brake (passive braking system). In the event of operating disturbances, an energy accumulation takes place in compressed-air reservoirs in the case of electropneumatic systems, in hydraulic reservoirs in the case of electrohydraulic systems and, in the form of pre-loaded springs in the case of electromechanical systems.
From the prior art, electromechanical brake tightening devices for rail vehicles are known which have a brake actuator which comprises a service brake unit as well as an accumulator-type brake unit having an energy accumulator. The service brake unit contains a braking power generator for the application and/or release of the brake, for example, in the form of an electric motor drive. The accumulator-type brake unit comprises at least one energy accumulator for storing and supplying energy for the application of the brake as a service-type emergency brake in the sense of an underlying safety plane in the event of a failure of the service brake unit and/or as the parking brake. The accumulator-type brake unit is generally constructed as a spring-loaded brake.
A power converter provides a conversion of the energy supplied by the braking power generator and/or by the energy accumulator into a brake application movement. The electric-motor drive can be controlled by an electronic control and power system to carry out slip-controlled or load-corrected brakings. For the desired-actual comparison, values are required for the respectively present actual braking power, so that sensors for the direct braking power measurement or for measuring quantities from which the actual braking power can be derived have to be provided.
In the case of electropneumatic and electrohydraulic braking systems, pressure sensors are generally used for measuring the operating pressure existing in the compressed air or in the hydraulic liquid, from which operating pressure the amount of the momentary braking power can then be derived. However, such mediums do not exist in the case of electromechanical systems.